Bridge conditions in Iroquois County, Illinois 568 inventoried bridges · 83 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions 2025 National Bridge Inventory, FHWA Compiled August 20, 2026
Of the 568 Iroquois County bridges in the federal inventory, 83 carry a poor rating. That 14.6% share is roughly 2x the national average.
83 of the 568 bridges in Iroquois County, Illinois, are rated in poor condition (14.6%) in the 2025 National Bridge Inventory, as of August 20, 2026 .258 bridges (45.4%) are rated good and 227 (40.0%) fair.
The median Iroquois County bridge was built in 1983 .
The busiest poor-rated bridge is Fai-57 NB over Ic RR (built 1967), carrying about 9,050 vehicles a day.
Good 45.4% · Fair 40.0% · Poor 14.6% of 568 bridges
Bridges rated poor Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
Bridge Built Vehicles/day Condition Fai-57 NB over Ic RR 1967 9,050 Poor Fai-57 SB over T.p. & W RR 1967 9,050 Poor Fai-57 SB over West Second St 1967 9,050 Poor Fai-57 NB over Prairie CR 1967 9,050 Poor Fai-57 SB over Prairie Creek 1967 9,050 Poor Fai-57 SB over Louis Creek 1968 8,750 Poor Fai 57 NB over Louis Creek 1968 8,750 Poor US 45-52 over Langan CR 1952 3,650 Poor US 45 & US 52 over Prairie Creek 1952 3,250 Poor Ill 1 over Little Beaver Creek 1918 2,000 Poor US 52 over Pike Creek 1928 1,700 Poor Fas-330 CH31 over Iroquois River 1965 1,200 Poor Ill 54 over I 57 1967 1,150 Poor Fas 334 /C.H.9 over Fai 57 1968 1,050 Poor Ill 49 over Br Pigeon Creek 1990 1,050 Poor Ill 49 over Shavetail Creek 1927 1,000 Poor Fas 321 (ch 4) over I-57 1965 825 Poor Tr-290 over Pike Creek 1965 825 Poor Ch 29 over I-57 1965 800 Poor Tr 14 over Trib Spring Creek 1972 300 Poor Fas 323 Ch 40 over Possum Trot Ditch 1938 300 Poor Danforth Rd Fas 33 over I-57 1967 200 Poor Tr 91 B over Pike Creek 1958 200 Poor Fas 1343 Ch 41 over Branch Sugar Creek 1959 175 Poor Tr-290 over Martinton Ditch #3 1959 175 Poor CH 47 / 1200 N Rd over Fai-57 1968 150 Poor Fas1335ch42 over Trib Little Mud CR 1918 150 Poor Tr 2C over Hooper Branch 1968 150 Poor Tr 339 over Pigeon CR 1967 150 Poor Tr 55B over Martinton Dch No 3 1927 125 Poor Colfax St over Trib of Spring CR 1900 125 Poor Tr 327 MFT108TR over Louis Creek 1960 100 Poor Tr 327 over Louis Creek 1966 100 Poor Tr 26A Mft 110 Tr over Louis Creek 1916 75 Poor Tr 282 over Trib Sugar Creek 1910 75 Poor Tr 140 over Trib Praire CR 1962 75 Poor Tr 442 over Trib to Iroquois Rv 1952 75 Poor Tr 104 over Trib Prairie Creek 1976 75 Poor Tr 155 over Praire Creek 1976 75 Poor Tr 84 over Br of Spring Creek 1953 75 Poor Tr 359 over Trib to Pigeon CR 1925 75 Poor Tr 280 over Trib. to Mud CR 1971 75 Poor Tr 217 over Spring CR 1965 75 Poor Tr 331A over Stream 1976 75 Poor Tr 285 over Trib to Sugar Creek 1983 75 Poor Tr 284 (old Rt 1) over Br Sugar Creek 1930 50 Poor Tr 126 over Little Mud CR 1970 50 Poor Tr 126 over Mud CR 1954 50 Poor Tr 2 over Stream 1959 50 Poor Tr 108 over Langan Creek 1983 50 Poor Tr 41 over Langan Creek 1985 50 Poor Tr 565 over Spring CR 1915 50 Poor Tr 44A over Trib Langan Creek 1956 50 Poor Tr 30 over W. Br Langan CR 1965 50 Poor Tr 345B over Trib Little Mud Ck 1920 50 Poor Tr 1 over Trib to Pigeon CR 1981 50 Poor Tr 352 over Trib Mud CR 1967 50 Poor Tr 2E over Stream 1914 50 Poor Tr 396 over Trib to Sugar CR 1907 50 Poor Tr 434 over Sugar CR 1921 50 Poor Tr 2 D over Trib to Sugar CR 1965 50 Poor Tr 317 over Unnamed Tributary 1995 50 Poor Tr 1 over Fountain CR 1958 50 Poor Tr 293 over Little Mud Creek 1971 25 Poor Tr 22B over Louis Creek 1964 25 Poor Tr 228 over Mud CR 1914 25 Poor Tr 49 B over Prairie CR 1904 25 Poor Tr 245 over Coon Creek 1916 25 Poor Tr 276 over Coon Creek 1916 25 Poor Tr 89 over Prairie CR 1976 25 Poor Tr 135 over Praire Creek 1924 25 Poor Tr 22 over Prairie CR 1934 25 Poor Tr 94A over Trib. to Spring CR 1928 25 Poor Tr 104 over Trib to Spring CR 1956 25 Poor TR97 over Drainage Ditch 1987 25 Poor Tr 341 over Gay Creek 1967 25 Poor Tr 320 over Martinton Ditch #3 1955 25 Poor Tr 242 over Mud CR 1917 25 Poor Tr 228 over Jefferson CR 1910 25 Poor Tr 16 over Stream 1964 25 Poor Tr 351 over Trib to Pigeon CR 1961 25 Poor Tr 452 over Stream 1977 25 Poor Tr 10B MFT120 over Louis Creek 1962 20 Poor
Busiest bridges in the county Bridge Built Vehicles/day Condition I-57 over Dranage Ditch 2015 18,100 Fair I-57 over Dranage Ditch 2015 18,100 Fair I-57 NB & SB over Prairie Creek 2015 18,100 Fair Fai-57 over Stream 1971 17,600 Fair I-57 SB over Langan Creek 2013 9,550 Fair Fai-57 NB over Langan Creek 2014 9,550 Fair Fai-57 NB over Fas 317 & Icg RR 1966 9,200 Fair Fai-57 SB over Fas 317 & Icg RR 1966 9,200 Fair Fai-57 SB over Ic RR 1967 9,050 Fair Fai-57 NB over Ic RR 1967 9,050 Poor
Source: FHWA National Bridge Inventory , 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
Every bridge in Iroquois County →
All of Illinois: Illinois bridge conditions by county · every download on the data page .
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected .